P21 Interleaved Parallel Routing 交替平行路由

Pattern 21 Interleaved Parallel Routing 交替平行路由 A set of tasks has a partial ordering defining the requirements with respect to the order in which they must be executed. Each task in the set must be executed once and they can by completed in any order that accords with the partial order. However, as an additional requirement, no two tasks can be executed at the same time (i.e. no two tasks can be active for the same process instance at the same time). 一组活动以任意的顺序执行，每个活动都被执行，他们的顺序是在运行时决定的，并且在任意一个时刻都不会有两个活动在执行。